A redox reaction using an oxidoreductase as a catalyst is known as a general method for measuring a specified component in a sample, for example, the glucose level in blood. On the other hand, personal blood glucose level measuring devices of a size such that they can be held in the palm of the hand have been used to determine the blood glucose level in a simple manner at home or on the trip. In such personal blood glucose level measuring devices, the measurements of blood glucose level are conducted, for example, by mounting a disposable biosensor which is employed for providing an enzyme reaction field in the device and then supplying blood into the biosensor (for example, see JP-B 8-10208).
In the biosensor, a reduction product (or oxidation product) is produced in the amount corresponding to the blood glucose level in the enzyme reaction field. At this time, if a voltage is applied to the enzyme reaction field via electrodes, an electron exchange proceeds between the reduction product (or oxidation product) and the electrode. The quantity of this electron exchange is measured as an oxidation current (or reduction current) in the personal blood glucose level measuring device, and the blood glucose level is computed based on the resulting current.
Because the reaction rate in the enzyme reaction is comparatively strongly depends on temperature, the amount of the produced reduction product (or oxidation product) is easily affected not only by the blood glucose level, but also by the reaction temperature. For this reason, some personal blood glucose level measuring devices were constructed so that the final measurement results were calculated after making a correction for temperature. Temperature measurements in this case are conducted by measuring the internal temperature of the blood glucose level measuring device, for example, with a temperature sensor incorporated in the blood glucose level measuring device. On the other hand, temperature correction can be also conducted by incorporating a temperature sensor in a biosensor and supplying the temperature information from the biosensor to the blood glucose level measuring device.
However, the method for measuring the temperature inside the blood glucose level measuring device does not measure the temperature (reaction temperature) of the biosensor. Therefore, the results obtained do not necessarily reflect the reaction temperature. On the other hand, with the method in which the biosensor is provided with the temperature sensor, the biosensor temperature can be adequately determined, but a temperature sensor has to be provided for each biosensor, thereby making the biosensor more expensive. Therefore, when a disposable biosensor is constructed, it is impractical to provide the biosensor with a temperature sensor. This is why it is necessary to modify the configuration of not only biosensors but also personal blood glucose level measuring devices. For example, it is necessary to provide a personal blood glucose level measuring device with an input unit for receiving temperature information from the biosensor.